CVE-2025-63638 Overview
CVE-2025-63638 is a stored Cross-Site Scripting (XSS) vulnerability affecting Sourcecodester AI-Powered To-Do List App v1.0, developed by remyandrade. The application fails to sanitize user-supplied input in the Task Title and Description (Optional) fields when creating a task. An attacker can inject arbitrary HTML or JavaScript that executes in the victim's browser after the Add Task button is clicked. The flaw is tracked under CWE-79: Improper Neutralization of Input During Web Page Generation.
Critical Impact
Attackers can execute arbitrary JavaScript in a victim's browser session, enabling session data theft, UI defacement, and client-side redirection through the task creation workflow.
Affected Products
- Sourcecodester AI-Powered To-Do List App v1.0
- remyandrade ai-powered_to-do_list_app 1.0
- CPE: cpe:2.3:a:remyandrade:ai-powered_to-do_list_app:1.0:*:*:*:*:*:*:*
Discovery Timeline
- 2025-11-07 - CVE-2025-63638 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-63638
Vulnerability Analysis
The AI-Powered To-Do List App renders user-provided task metadata directly into the Document Object Model (DOM) without HTML entity encoding or input sanitization. When a user submits a task, the values from the Task Title and Description (Optional) fields are inserted into the task list view. Payloads containing HTML tags or <script> blocks are parsed and executed by the browser.
Because the application is a client-side JavaScript project, the injected payload runs in the same origin as the victim's session. This allows attackers to access localStorage, manipulate the DOM, and issue outbound requests using the victim's credentials in any authenticated integrations.
Root Cause
The root cause is missing output encoding when rendering task input. The application likely uses innerHTML assignment or an equivalent unsafe DOM API instead of textContent or a templating engine with automatic escaping. Neither client-side validation nor a Content Security Policy (CSP) is present to constrain script execution.
Attack Vector
Exploitation requires user interaction. An attacker crafts a malicious payload in the Task Title or Description field and induces the victim to load the tainted task. Once the Add Task button is pressed or the task list is rendered, the payload executes. Delivery vectors include shared task lists, social engineering, or persistent storage if the app synchronizes state between users.
No verified proof-of-concept code is published in the referenced repositories. Refer to the GitHub CVE-2025-63638 Research for technical write-up details.
Detection Methods for CVE-2025-63638
Indicators of Compromise
- Task entries containing HTML tags such as <script>, <img onerror=...>, or <svg onload=...> in stored application data.
- Unexpected outbound browser requests to attacker-controlled domains originating from the to-do application origin.
- Browser console errors or Content Security Policy violations logged when the task list is rendered.
Detection Strategies
- Inspect stored task records for HTML control characters (<, >, ", ') that were not neutralized before storage.
- Deploy a web application firewall (WAF) rule to flag task submission payloads matching common XSS signatures.
- Review browser telemetry and endpoint logs for anomalous JavaScript execution originating from the application domain.
Monitoring Recommendations
- Enable CSP report-only mode to capture inline script violations without breaking functionality.
- Monitor HTTP POST requests to task creation endpoints for encoded script fragments and event handler attributes.
- Alert on session anomalies such as unexpected token access, cookie exfiltration attempts, or DOM-based redirects.
How to Mitigate CVE-2025-63638
Immediate Actions Required
- Restrict access to the AI-Powered To-Do List App v1.0 until sanitization controls are in place.
- Clear existing task storage that may contain persisted XSS payloads from prior submissions.
- Instruct users to avoid loading task lists received from untrusted parties.
Patch Information
No official vendor patch is referenced in the NVD entry at the time of publication. Consult the Sourcecodester project page and the vulnerability research repository for update status. Operators maintaining forks should apply output encoding to task rendering paths.
Workarounds
- Replace innerHTML assignments with textContent or Element.setAttribute calls that do not parse HTML.
- Apply a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins.
- Sanitize task input server-side and client-side using a vetted library such as DOMPurify before storage or rendering.
# Content Security Policy header example for the application host
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'none'
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
